1. Field of the Invention
The present invention relates to a steering system in which an outboard engine is controlled to turn by an electric motor and more particularly to a steering system having an additional function to deal with a case where an anomaly of a turn angle sensor for detecting a turn angle of an outboard engine occurs.
2. Description of Related Art
JP-A-2005-280579 describes an electric steering system which utilizes an electric motor, as a vessel steering system. In JP-A-2005-280579, the vessel steering system includes an actuator for turning an outboard engine, a turn angle sensor for detecting a turn angle of the outboard engine, a steering wheel sensor for detecting a rotational angle of a steering wheel, and an actuator controller for outputting a control signal to the actuator in response to signals from the turn angle sensor and the steering wheel sensor. In the vessel steering system, the steering wheel and the outboard engine are connected only electrically. A turn angle is determined based on an amount in which the steering wheel is operated, and the actuator is driven by the value of the determined turn angle such that the outboard engine is turned as intended by an operator.
In addition, JP-A-2007-126023 proposes a use of two or more actuator controllers or one actuator for a plurality of outboard engines, and doesn't propose a use of one actuator and one controller for one outboard engine.